The invention relates to power switching semiconductors, and more particularly to power MOSFETs (metal oxide semiconductor field effect transistors), and the like.
Lateral FET structure is provided for bidirectional power switching, including AC application. A common drift region is between first and second stacks of alternating conductivity type layers, each stack having a plurality of channel-containing regions interleaved with a plurality of source regions. The channels are gated ON by inverting the conductivity type thereof to afford bidirectional conduction serially through the stacks and the drift region. In the OFF state, the plurality of junctions in series between the layers of the stacks affords increased OFF state voltage blocking capability.
In preferred form, a semiconductor body is provided having a plurality of alternating conductivity type layers extending laterally horizontally, and stacked vertically. A notch is etched downwardly through the plurality of alternating conductivity type layers and into a drift region therebelow. The notch separates the layers into first and second laterally spaced stacks, each stack having a plurality of channel-containing regions interleaved with a plurality of source regions. A first main electrode contacts the top left source region, and a second main electrode contacts the top right source region. Insulated gate electrode means is disposed in the notch in close proximity to the layers of the stacks. The conductive current path traverses serially through the layers of one stack along one side of the notch, then through the drift region around the bottom of the notch, then serially through the layers of the other stack along the other side of the notch.